Web-format polishing pads and methods for manufacturing and using web-format polishing pads in mechanical and chemical-mechanical planarization of microelectronic substrates

ABSTRACT

A web-format polishing pad for mechanical and/or chemical-mechanical planarization of microelectronic substrate assemblies, and methods for making and using such a web-format pad. In one aspect of the invention, a web-format polishing pad for planarizing a microelectronic substrate is made by slicing a cylindrical body of pad material along a cutting line that is at least substantially parallel to a longitudinal centerline of the body and at a radial depth inward from an exterior surface of the body. For example, a web of pad material can be sliced from the body by rotating the cylindrical body about the longitudinal centerline and pressing a cutting element against the rotating cylindrical body along the cutting line. The cutting element can be a knife with a sharp edge positioned at the cutting line and a face extending along a tangent of the cylindrical body. The cutting element can be moved radially inwardly as the body rotates to continuously peel a seamless web of pad material having a desired thickness from the cylindrical pad body. The web of pad material accordingly may be used on a web-format planarizing machine for planarizing microelectronic substrate assemblies.

TECHNICAL FIELD

[0001] The present invention generally relates to planarizingsemiconductor wafers, field emission displays, and other microelectronicsubstrate assemblies used in the fabrication of microelectronic devices.More particularly, the invention is directed towards web-formatpolishing pads, and methods for making and using web-format polishingpads in mechanical and/or chemical-mechanical planarization ofmicroelectronic substrates.

BACKGROUND OF THE INVENTION

[0002] Mechanical and chemical-mechanical planarizing processes(collectively “CMP”) are used in the manufacturing of microelectronicdevices for forming a flat surface on semiconductor wafers, fieldemission displays and many other microelectronic substrate assemblies.FIG. 1 schematically illustrates a planarizing machine 10 with acircular platen or table 20, a carrier assembly 30, a circular polishingpad 40, and a planarizing fluid 44 on the polishing pad 40. Theplanarizing machine 10 may also have an under-pad 25 attached to anupper surface 22 of the platen 20 for supporting the polishing pad 40.In many planarizing machines, a drive assembly 26 rotates (arrow A)and/or reciprocates (arrow B) the platen 20 to move the polishing pad 40during planarization.

[0003] The carrier assembly 30 controls and protects a substrate 12during planarization. The carrier assembly 30 typically has a substrateholder 32 with a pad 34 that holds the substrate 12 via suction. A driveassembly 36 of the carrier assembly 30 typically rotates and/ortranslates the substrate holder 32 (arrows C and D, respectively). Thesubstrate holder 32, however, may be a weighted, free-floating disk (notshown) that slides over the polishing pad 40.

[0004] The combination of the polishing pad 40 and the planarizing fluid44 generally define a planarizing medium that mechanically and/orchemically-mechanically removes material from the surface of thesubstrate 12. The polishing pad 40 may be a conventional polishing padcomposed of a polymeric material (e.g., polyurethane) without abrasiveparticles, or it may be an abrasive polishing pad with abrasiveparticles fixedly bonded to a suspension material. In a typicalapplication, the planarizing fluid 44 may be a CMP slurry with abrasiveparticles and chemicals for use with a conventional nonabrasivepolishing pad. In other applications, the planarizing fluid 44 may be achemical solution without abrasive particles for use with an abrasivepolishing pad.

[0005] To planarize the substrate 12 with the planarizing machine 10,the carrier assembly 30 presses the substrate 12 against a planarizingsurface 42 of the polishing pad 40 in the presence of the planarizingfluid 44. The platen 20 and/or the substrate holder 32 then moverelative to one another to translate the substrate 12 across theplanarizing surface 42. As a result, the abrasive particles and/or thechemicals in the planarizing medium remove material from the surface ofthe substrate 12.

[0006] CMP processes must consistently and accurately produce auniformly planar surface on the substrate to enable precise fabricationof circuits and photo-patterns. Prior to being planarized, manysubstrates have large “step heights” that create a highly topographicsurface across the substrate. Yet, as the density of integrated circuitsincreases, it is necessary to have a planar substrate surface at severalstages of processing the substrate because non-uniform substratesurfaces significantly increase the difficulty of forming sub-micronfeatures or photo-patterns to within a tolerance of approximately 0.1μm. Thus, CMP processes must typically transform a highly topographicalsubstrate surface into a highly uniform, planar substrate surface (e.g.,a “blanket surface”).

[0007] One particularly promising planarizing machine to enhance theplanarity of the substrates is a web-format machine that uses a long,flexible polishing pad. FIG. 2 is a schematic isometric view of aweb-format planarizing machine 100 similar to a machine manufactured byEDC Corporation. The planarizing machine 100 may have a support table110 with a base 112 at a workstation A defining a planarizing zone. Thebase 112 is generally a rigid panel or plate attached to the table 110to provide a flat, solid surface to which a portion of a web-formatplanarizing pad 140 is supported during planarization. The planarizingmachine 100 also has a plurality of rollers to guide, position, and holdthe web-format pad 140 over the base 112. The rollers generally includea supply roller 120, first and second idler rollers 121 a and 121 b,first and second guide rollers 122 a and 122 b, and a take-up roller123. The supply roller 120 carries an unused or pre-operative portion ofthe web 140, and the take-up roller 123 carries a used or post-operativeportion of the web 140. A motor (not shown) drives at least one of thesupply and take-up rollers to sequentially advance the web 140 acrossthe base 112. As such, unused portions of the web 140 may be quicklysubstituted for worn sections. The first idler roller 121 a and thefirst guide roller 122 a stretch the web 140 over the base 112 to holdthe web 140 stationary during operation.

[0008] The planarizing machine 100 also has a carrier assembly 130 totranslate the substrate 12 across the web 140. In one embodiment, thecarrier assembly 130 has a substrate holder 132 to pick up, hold andrelease the substrate 12 at appropriate stages of the planarizingprocess. The carrier assembly 130 may also have a support gantry 134carrying a drive assembly 135. The drive assembly 135 generallytranslates along the gantry 134, and the drive assembly 135 has anactuator 136, a drive shaft 137 coupled to the actuator 136, and an arm138 projecting from the drive shaft 137. The arm 138 carries thesubstrate holder 132 via another shaft 139. The drive assembly 135 mayalso have another actuator (not shown) to rotate the shaft 139 and thesubstrate holder about an axis C-C as the actuator 136 orbits thesubstrate holder 132 about the axis B-B.

[0009] One processing concern associated with web-format planarizingmachines is that the web-format polishing pad 140 may produce surfaceasperities on the substrates, such as gouges, scratches or localizedrough areas that exceed normal surface non-uniformities across anadequately planarized substrate. More particularly, conventionalweb-format polishing pads have a plurality of sections 146 attached toone another along seams 147. As a substrate passes over the pad 140, theseams 147 may gouge the substrate and produce asperities on thesubstrate surface. The seams 147 may even severely damage a substrate inmore aggressive CMP processes or on softer materials. Additionally, theplanarizing characteristics may vary from one pad section 146 toanother. Therefore, conventional web-format polishing pads have severaldrawbacks that may adversely impact the planarity of the finishedsubstrates.

[0010] In addition to such processing concerns, web-format polishingpads also have several manufacturing concerns. FIG. 3 is a schematicisometric view of a process for making a conventional web-formatpolishing pad in which a cylindrical body 150 of pad material (e.g.,polyurethane) is formed in a mold (not shown). A number of individualcircular polishing pads 40, which are generally used with the rotationalplanarizing machine 10 shown in FIG. 1, are formed from the cylindricalbody 150. Each circular polishing pad 40 is generally formed by cuttingthe cylindrical body 150 along a cutting line substantially normal tothe longitudinal center line “C/L” of the cylindrical body 150. To adaptthe circular pads 40 for use in a web-format planarizing machine, arectilinear pad section 146 is then cut from a circular polishing pad40. The rectilinear pad sections 146 are then attached to one another toform the web-format polishing pad 140 with a plurality of seams 147(FIG. 2).

[0011] One particular manufacturing concern of fabricating web-formatpolishing pads is that trimming the circular polishing pads 40 to formthe rectilinear pad sections 146 is time consuming and wastes asignificant amount of pad material. Another manufacturing concern offabricating web-format polishing pads is that most planarizing machinescurrently in use require circular polishing pads 40 that fit on arotating platen. Many pad manufacturers, therefore, are reticent todevelop rectilinear molds for forming a rectilinear body of padmaterial. Thus, it is wasteful and time consuming to use existingpolishing pad manufacturing equipment and processes to produceweb-format pads.

SUMMARY OF THE INVENTION

[0012] The present invention is directed towards web-format polishingpads for mechanical and/or chemical-mechanical planarization ofmicroelectronic substrate assemblies, along with methods for making andusing such web-format pads. In one aspect of the invention, a web-formatpolishing pad is made by slicing a cylindrical body of pad materialalong a cutting line that is at least substantially parallel to alongitudinal centerline of the body and at a radial depth inward from anexterior surface of the body. For example, a web of pad material can besliced from the cylindrical body by rotating the body about thelongitudinal centerline and pressing a cutting element against therotating cylindrical body along the cutting line. The cutting elementcan be a knife with a sharp edge positioned at the cutting line and aface extending along a tangent of the cylindrical body. Additionally, anactuator can move the cutting element radially inwardly as the bodyrotates to continuously peel a seamless web of pad material having adesired thickness from the cylindrical pad body. The web of pad materialaccordingly may be used on a web-format planarizing machine forplanarizing microelectronic substrates.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a schematic cross-sectional view of a planarizingmachine with a rotating platen in accordance with the prior art.

[0014]FIG. 2 is a schematic isometric view of a web-format planarizingmachine with a web-format polishing pad in accordance with the priorart.

[0015]FIG. 3 is an isometric view illustrating the manufacturing of aweb-format polishing pad in accordance with the prior art.

[0016]FIG. 4 is an isometric view of a web-format polishing pad and amethod for making the web-format polishing pad in accordance with oneembodiment of the invention.

[0017]FIG. 5A is a partial cross-sectional view at one stage of themethod for manufacturing the web-format polishing pad shown in FIG. 4taken along line 5-5.

[0018]FIG. 5B is a partial cross-sectional view at a subsequent stage ofthe method for manufacturing the web-format polishing pad shown in FIG.4 taken along line 5-5.

[0019]FIG. 6 is an isometric view of a planarizing machine and a processof planarizing a microelectronic substrate on a seamless web-formatpolishing pad in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention is directed toward web-format polishingpads, and methods for manufacturing and using such polishing pads, formechanical and/or chemical-mechanical planarization of microelectronicsubstrate assemblies. Many specific details of certain embodiments ofthe invention are set forth in the following description and in FIGS.4-6 to provide a thorough understanding of such embodiments. One skilledin the art, however, will understand that the present invention may haveadditional embodiments, or that the invention may be practiced withoutseveral of the details described in the following description.

[0021]FIG. 4 is a schematic isometric view of a cutting machine 200illustrating a method for manufacturing a seamless web-format polishingpad 240 in accordance with one embodiment of the invention. The cuttingmachine 200 can have a housing 202 with a plurality of arms 204projecting from an upper portion of the housing 202. The cutting machine200 also includes a drive motor 206, a rotating chuck 208, and a drivemechanism 210 coupling the rotating chuck 208 to the drive motor 206.Each chuck 208 grips an end of a molded cylindrical body 250 ofpolishing pad material. For example, each chuck 208 can have a pluralityof fingers 209 (shown in broken lines) that penetrate into the body 250of pad material. The motor 206 accordingly drives the chucks 208 via thedrive mechanism 210 to rotate the body 250 (arrow R) about itslongitudinal centerline 254.

[0022] The cutting machine can also have a cutting assembly 220 mountedto the arms 204. The cutting assembly 220 preferably has a cuttingelement 222 with a cutting edge 223, and a bracket 224 at each end ofthe cutting element 222 (only one shown in FIG. 4). The bracket 224holds the cutting element 222 at a desired elevation with respect to thearms 204. Each of the brackets 224 may also be coupled to an actuator226 to move the brackets 224 and the cutting element 222 vertically(arrow V) and/or longitudinally (arrow L). As explained in more detailbelow, the drive motor 206 and the actuator 226 are both coupled to acontroller 228 that controls the rotational velocity of the chuck 208and the movement of the cutting element 222 to slice or peel a seamlessweb 240 from the body 250.

[0023] The cutting element 222 may have several differentconfigurations. For example, the cutting element 222 can be a knife witha sharp cutting edge 223. Alternatively, the cutting element 222 can bea saw in which the cutting edge 223 has a plurality of fine teeth. Ineither type of cutting element, the actuator 226 moves the cuttingassembly 220 vertically (arrow V) and may also reciprocate the cuttingassembly 220 longitudinally (arrow L).

[0024] To manufacture a seamless web-format polishing pad 240, thecylindrical molded body 250 of pad material is mounted to the rotatingchuck 208 of the cutting machine 200. The motor 206 rotates the chuck208 to rotate the cylindrical body 250 (arrow R), and the actuator 226positions the cutting element 222 at a radius 256 of the cylindricalbody 250 inward from an exterior surface 252 of the body 250. As thecylindrical body 250 rotates, the cutting element 222 slices or peels acontinuous web of pad material along a cutting line at leastsubstantially parallel to the longitudinal center line 254 of the body250. The cutting machine 200 accordingly forms a seamless web-formatpolishing pad 240.

[0025]FIGS. 5A and 5B are schematic cross-sectional views along line 5-5of FIG. 4 that further illustrate one embodiment for manufacturing aseamless web-format polishing pad 240 in accordance with the invention.Referring to FIG. 5A, the motor 206 (FIG. 4) rotates the cylindricalbody 250 (arrow R) and the actuator 226 (FIG. 4) moves the cuttingassembly 220 downward (arrow V) toward the centerline 254 to locate thecutting edge 223 at a radial depth D inward from the exterior surface252. Additionally, the cutting edge 223 extends along a cutting line 255that is at least substantially parallel to the longitudinal centerline254 (e.g., the cutting line 255 and the longitudinal centerline 254extend parallel to a Z-axis normal to the X-Y plane of thetwo-dimensional view of FIG. 5A). As the cylindrical body 250 rotates,the controller 228 (FIG. 4) preferably controls the actuator 226 to movethe cutting assembly 220 downward at a rate that continuously positionsthe cutting edge 223 at a constant radial depth from the exteriorsurface 252 of the body 250. Referring to FIG. 5B, for example, thecutting assembly 220 has been moved toward the longitudinal center line254 of the cylindrical body 250 to continuously slice the seamless web240 such that the thickness of the web 240 is equal to the radial depthD. The controller 228, however, can move the cutting element 222 to varythe thickness of the web. Accordingly, the controller 228 may beprogrammed to control the actuator 226 and the motor 206 in a mannerthat moves the cutting assembly 220 toward the longitudinal center lineof the body 250 in a predetermined relationship to the angular velocityof the cylindrical body 250. Programming the controller 228 according tothe particular angular velocity of the pad body 250 and the linearvelocity of the cutting assembly 220 is well within the knowledge of aperson skilled in the art using known algorithms developed in the art ofcutting wood plies in the manufacturing of plywood.

[0026] The cylindrical body 250 may be composed of several differentmaterials. In general, the cylindrical body 250 may be a matrix of castpolyurethane film with a filler material to control the hardness of thepolishing pads. Suitable cylindrical bodies of pad material aremanufactured by Rodel Corporation of Newark, N.J. For example, seamlessweb-format polishing pads, in accordance with the invention, may bemanufactured as set forth above with respect to FIGS. 4-5B fromcylindrical bodies composed of the following pad materials:

[0027] (1) A Rodel Suba IV pad material having a specific gravity of0.3, a compressibility of 16%, and a hardness of 55 (Shore A);

[0028] (2) A Rodel Suba 500 pad material having a specific gravity of0.34, a compressibility of 12% and a hardness of 65 (Shore A);

[0029] (3) A Rodel IC-60 pad material having a specific gravity of 0.7,a very low compressibility less than 5%, and a hardness of 52-60 (ShoreD);

[0030] (4) A Rodel IC-1000 polishing pad material having a specificgravity of 0.6-0.8, a compressibility of 5% or less, and a hardnessgreater than 52-60 (Shore D); and

[0031] (5) A fixed-abrasive pad material having abrasive particlesfixedly bonded to a suspension medium, as disclosed in U.S. Pat. No.5,624,303, which is herein incorporated by reference.

[0032] Other types of polishing pad material may be used havingdifferent specific gravities, compressibilities and hardnesses. Ingeneral, the specific gravity indicates the pad porosity such that lowspecific gravities correspond to highly porous pads. Additionally,hardness and compressibility/resiliency features of the polishing padsare important because hard, substantial non-compressible polishing padsgenerally produce better global planarity on a substrate surface. Thus,the polishing pad material may be any suitable polymeric material, orother type of material, having the appropriate porosity, hardness andcompressibility/resiliency properties to planarize a microelectronicsubstrate assembly.

[0033]FIG. 6 is a schematic isometric view illustrating planarizing amicroelectronic substrate 12 on a seamless web-format polishing pad 240in accordance with an embodiment of the invention. The polishing pad 240is a continuous, seamless web of pad material having a planarizingsurface 242 and a length extending beyond the table 210 of theplanarizing machine 100. The polishing pad 240 accordingly has a firstportion wrapped around the supply roller 120, a second portion on thetable 110, and a third portion wrapped around the take-up roller 123. Inoperation, the carrier assembly 130 presses the substrate 12 against theplanarizing surface 242 of the seamless polishing pad 240, and thecarrier assembly 130 drives the substrate holder 132 to move thesubstrate 12 with respect to the polishing pad 240. A planarizingsolution, such as a slurry with abrasive particles or a non-abrasiveliquid 144, flows from a plurality of nozzles 138 on the substrateholder 132 as the substrate 12 translates across the pad 240. Theabrasive particles and/or the chemicals on the planarizing surface 242of the pad 240 accordingly remove material from the face of thesubstrate 12.

[0034] The seamless pad 240 may also be incrementally moved across thetable 110 either during or between planarizing cycles to change theparticular portion of the polishing pad 240 in a planarizing zonedefined by the motion of the substrate holder 132 and/or the table 110.For example, the supply and take-up rollers 120 and 123 can drive thepolishing pad 240 such that a point P moves incrementally across thetable 110 to a number of intermediate locations I₁, I₂, etc.Alternatively, the rollers 120 and 123 may drive the polishing pad 240such that the point P moves all the way across the table 110 tocompletely remove a used portion of the pad 240 from the planarizingzone on the table 110. The rollers may also continuously drive thepolishing pad at a slow rate such that the point P moves continuouslyacross the table 110.

[0035] One aspect of the particular embodiment of the process formanufacturing the seamless polishing pad 240 is that it significantlyreduces the time and waste associated with conventional processes thatcut rectilinear sections from circular pads to fabricate a conventionalweb-format pad. For example, the process described above with respect toFIGS. 4-5B does not require separately attaching individual pad sectionstogether along abutting edges. Additionally, compared to conventionalmethods, forming the seamless polishing pad 240 using the cuttingmachine 200 is expected to reduce the waste of pad material. Therefore,several embodiments of methods in accordance with the invention areexpected to reduce the time and waste for producing web-format polishingpads.

[0036] Another aspect of manufacturing the seamless polishing pad 240 inaccordance with the particular embodiment described above is thatconventional cylindrical molds for circular pads may be used to form aseamless web-format polishing pad. Pad manufacturers can accordinglymake both circular pads and seamless web-format pads without changingmolds or developing new molding processes. As such, several embodimentsof the invention are also expected to significantly simplify polishingpad manufacturing operations.

[0037] Still another aspect of the particular embodiment of planarizinga microelectronic substrate on the seamless polishing pad 240 is that itis expected to reduce the number and extent of surface asperities on thesubstrate surface compared to conventional web-format polishing pads.Unlike conventional web-format polishing pads that have seams, thepolishing pad 240 is a continuous, seamless web-format pad. Accordingly,the seamless polishing pad 240 does not have seams that may gouge orotherwise produce asperities on the substrate surface.

[0038] From the foregoing it will be appreciated that, although specificembodiments of the invention have been described herein for purposes ofillustration, various modifications may be made without deviating fromthe spirit and scope of the invention. For example, after slicing theseamless web 240 from the cylindrical body 250 of pad material, theseamless web 240 may be adhered to a backing ply to enhance thestructural integrity of the web 240. One suitable material for thebacking ply is Mylar®, manufactured by E. I. duPont DeNemours ofDelaware. Accordingly, the invention is not limited except as by theappended claims.

1. In the fabrication of microelectronic devices, a method ofmanufacturing a planarizing medium for planarizing a microelectronicsubstrate assembly, comprising: slicing a cylindrical body of padmaterial along a cutting line at least substantially parallel to alongitudinal centerline of the body and at a radial depth inward from anexterior surface of the body toward the centerline to form a continuoussheet of pad material having a desired pad thickness.
 2. The method ofclaim 1 wherein slicing the cylindrical body comprises: positioning anedge of a cutting element along the cutting line; and rotating thecylindrical body against the cutting edge, the cutting edge peeling thesheet of pad material from the body.
 3. The method of claim 2 whereinpositioning the edge of the cutting element along the cutting linecomprises moving the cutting member radially inward toward thecenterline as the cylindrical body rotates.
 4. The method of claim 3wherein moving the cutting member comprises controlling the movement ofthe cutting member to maintain a desired radial depth inward from anexterior surface of the body as the cutting member slices the continuoussheet from the body.
 5. The method of claim 3 wherein moving the cuttingmember comprises controlling the movement of the cutting member tomaintain a constant radial depth inward from an exterior surface of thebody as the cutting member slices the continuous sheet from the body. 6.The method of claim 1 wherein slicing the cylindrical body comprisespeeling the continuous sheet from a cylindrical body of polymeric padmaterial having a specific gravity of approximately 0.3, acompressibility of approximately 16%, and a hardness of approximately 55Shore A.
 7. The method of claim 1 wherein slicing the cylindrical bodycomprises peeling the continuous sheet from a cylindrical body ofpolymeric pad material having a specific gravity of approximately 0.34,a compressibility of approximately 12%, and a hardness of approximately65 Shore A.
 8. The method of claim 1 wherein slicing the cylindricalbody comprises peeling the continuous sheet from a cylindrical body ofpolymeric pad material having a specific gravity of approximately 0.7, acompressibility of approximately 5%, and a hardness of approximately52-60 Shore D.
 9. The method of claim 1 wherein slicing the cylindricalbody comprises peeling the continuous sheet from a cylindrical body ofpolymeric pad material having a specific gravity of approximately0.6-0.8, a compressibility of approximately 2-7%, and a hardness ofapproximately 52-60 Shore D.
 10. The method of claim 1, furthercomprising adhering the sliced continuous sheet of pad material to abacking ply.
 11. The method of claim 1, further comprising adhering thesliced continuous sheet of pad material to a backing ply.
 12. In thefabrication of microelectronic devices, a method of manufacturing aplanarizing medium for planarizing a microelectronic substrate assembly,comprising: forming a cylindrical body of pad material, the body havinga longitudinal centerline and an exterior surface at a radial distancefrom the centerline; and peeling a web of pad material from the bodyalong a bifurcation line at least substantially parallel to thecenterline and at a desired radial distance inward from the exteriorsurface of the body.
 13. The method of claim 12 wherein forming thecylindrical body comprises molding and curing a polymeric material tohave a specific gravity of approximately 0.3, a compressibility ofapproximately 16%, and a hardness of approximately 55 Shore A.
 14. Themethod of claim 12 wherein forming the cylindrical body comprisesmolding and curing a polymeric material to have a specific gravity ofapproximately 0.34, a compressibility of approximately 12%, and ahardness of approximately 65 Shore A.
 15. The method of claim 12 whereinforming the cylindrical body comprises molding and curing a polymericmaterial to have a specific gravity of approximately 0.7, acompressibility of approximately 5%, and a hardness of approximately52-60 Shore D.
 16. The method of claim 12 wherein forming thecylindrical body comprises molding and curing a polymeric material tohave a specific gravity of approximately 0.6-0.8, a compressibility ofapproximately 2-7%, and a hardness of approximately 52-60 Shore D. 17.The method of claim 12 wherein peeling a web of pad material from thebody comprises: positioning an edge of a cutting element along thebifurcation line; and rotating the cylindrical body against the cuttingedge, the cutting edge slicing the sheet of pad material from the body.18. The method of claim 17 wherein positioning the edge of the cuttingelement along the bifurcation line comprises moving the cutting memberradially inward toward the centerline as the cylindrical body rotates tomaintain a desired radial depth inward from an exterior surface of thebody.
 19. In the fabrication of microelectronic devices, a method ofmanufacturing a planarizing medium for planarizing a microelectronicsubstrate assembly, comprising: rotating a cylindrical body of padmaterial, the body having a longitudinal centerline and an exteriorsurface at a radial distance from the centerline; pressing a cuttingmember against the rotating cylindrical body along a, cutting line atleast substantially parallel and at a desired radial distance inwardfrom the exterior surface of the body; and moving the cutting memberradially inwardly as the body rotates to continuously slice a web of padmaterial having a desired thickness.
 20. The method of claim 19 whereinmoving the cutting member comprises controlling the movement of thecutting member to maintain a desired radial depth inward from anexterior surface of the body as the cutting member slices the continuoussheet from the body.
 21. The method of claim 19 wherein moving thecutting member comprises controlling the movement of the cutting memberto maintain a constant radial depth inward from an exterior surface ofthe body as the cutting member slices the continuous sheet from thebody.
 22. A microelectronic device planarizing pad for planarizing amicroelectronic substrate assembly prepared by a process comprising:slicing a cylindrical body of pad material along a cutting line at leastsubstantially parallel to a longitudinal centerline of the body and at aradial depth inward from an exterior surface of the body toward thecenterline to form a continuous sheet of pad material having a desiredpad thickness.
 23. The pad of claim 22 prepared by slicing a cylindricalbody of pad material, wherein slicing the cylindrical body comprises:positioning an edge of a cutting element along the cutting line; androtating the cylindrical body against the cutting edge, the cutting edgepeeling the sheet of pad material from the body.
 24. The pad of claim 23prepared by slicing a cylindrical body of pad material, whereinpositioning the edge of the cutting element along the cutting linecomprises moving the cutting member radially inward toward thecenterline as the cylindrical body rotates.
 25. The pad of claim 24prepared by slicing a cylindrical body of pad material, wherein movingthe cutting member comprises controlling the movement of the cuttingmember to maintain a constant radial depth inward from an exteriorsurface of the body as the cutting member slices the continuous sheetfrom the body.
 26. The pad of claim 22 prepared by slicing a cylindricalbody of pad material, further comprising forming a polymeric cylindricalbody having a specific gravity of approximately 0.3, a compressibilityof approximately 16%, and a hardness of approximately 55 Shore A. 27.The pad of claim 22 prepared by slicing a cylindrical body of padmaterial, further comprising forming a polymeric cylindrical body havinga specific gravity of approximately 0.34, a compressibility ofapproximately 12%, and a hardness of approximately 65 Shore A.
 28. Thepad of claim 22 prepared by slicing a cylindrical body of pad material,further comprising forming a polymeric cylindrical body having aspecific gravity of approximately 0.7, a compressibility ofapproximately 5%, and a hardness of approximately 52-60 Shore D.
 29. Thepad of claim 22 prepared by slicing a cylindrical body of pad material,further comprising forming a polymeric cylindrical body having aspecific gravity of approximately 0.6-0.8, a compressibility ofapproximately 2-7%, and a hardness of approximately 52-60 Shore D.
 30. Amicroelectronic device planarizing pad for planarizing a microelectronicsubstrate assembly with a planarizing machine having a table defining aplanarizing zone, the pad comprising: a seamless web formed from acylindrical body of pad material, the web being slidable across thetable to move one portion of the web out of the planarizing zone and tomove another portion of the web into the planarizing zone withoutremoving the web from the table.
 31. The pad of claim 30 wherein the webcomprises a polymeric material.
 32. The pad of claim 30 wherein the webhas a planarizing surface and a backside opposite from the planarizingsurface, and the pad further comprises a backing ply attached to thebackside of the web.
 33. The pad of claim 32 wherein the web comprises apolymeric matrix material and the web has a specific gravity ofapproximately 0.3, a compressibility of approximately 16%, and ahardness of approximately 55 Shore A.
 34. The pad of claim 32 whereinthe web comprises a polymeric matrix material and the web has a specificgravity of approximately 0.34, a compressibility of approximately 12%,and a hardness of approximately 65 Shore A.
 35. The pad of claim 32wherein the web comprises a polymeric matrix material and the web has aspecific gravity of approximately 0.7, a compressibility ofapproximately 5%, and a hardness of approximately 52-60 Shore D.
 36. Thepad of claim 32 wherein the web comprises a polymeric matrix materialand the web has a specific gravity of approximately 0.6-0.8, acompressibility of approximately 2-7%, and a hardness of approximately52-60 Shore D.
 37. The pad of claim 32 wherein the web comprises apolymeric matrix material and a plurality of abrasive particles fixed tothe polymeric material, the abrasive particles being fixed to thepolymeric material at least at the planarizing surface.
 38. Amicroelectronic device planarizing pad for planarizing a microelectronicsubstrate assembly with a planarizing machine including a table and aroller, the pad comprising: a web of pad material having a planarizingsurface and a length to extend beyond the table and be wrapped aroundthe roller when the web is mounted to the planarizing machine, the webbeing a seamless sheet formed from a single molded body of the padmaterial.
 39. The pad of claim 38 wherein the web comprises a polymericmatrix material and the web has a specific gravity of approximately 0.3,a compressibility of approximately 16%, and a hardness of approximately55 Shore A.
 40. The pad of claim 38 wherein the web comprises apolymeric matrix material and the web has a specific gravity ofapproximately 0.34, a compressibility of approximately 12%, and ahardness of approximately 65 Shore A.
 41. The pad of claim 38 whereinthe web comprises a polymeric matrix material and the web has a specificgravity of approximately 0.7, a compressibility of approximately 5%, anda hardness of approximately 52-60 Shore D.
 42. The pad of claim 38wherein the web comprises a polymeric matrix material and the web has aspecific gravity of approximately 0.6-0.8, a compressibility ofapproximately 2-7%, and a hardness of approximately 52-60 Shore D.
 43. Aplanarizing machine, comprising: a table defining a planarizing zone; asupply roller proximate to the table; a take-up roller proximate to thetable, at least one of the supply roller and the take-up roller being adrive roller; a seamless pad including a web formed from a single moldedbody of pad material, the web having a first portion wrapped around thesupply roller, a second portion on the table in the planarizing zone,and a third portion wrapped around the take-up roller, the drive rollerrotating a selected distance to selectively slide the web across thetable; and a carrier assembly having a substrate holder positionableover the web, wherein at least one of the substrate holder or the webmoves relative to the other to translate the substrate with respect tothe web.
 44. The planarizing machine of claim 43 wherein the webcomprises a polymeric material.
 45. The planarizing machine of claim 43wherein the web has a planarizing surface and a backside opposite fromthe planarizing surface, and the pad further comprises a backing plyattached to the backside of the web.
 46. The planarizing machine ofclaim 45 wherein the web comprises a polymeric matrix material, and theweb has a specific gravity of approximately 0.3, a compressibility ofapproximately 16%, and a hardness of approximately 55 Shore A.
 47. Theplanarizing machine of claim 45 wherein the web comprises a polymericmatrix material, and the web has a specific gravity of approximately0.34, a compressibility of approximately 12%, and a hardness ofapproximately 65 Shore A.
 48. The planarizing machine of claim 45wherein the web comprises a polymeric matrix material, and the web has aspecific gravity of approximately 0.7, a compressibility ofapproximately 5%, and a hardness of approximately 52-60 Shore D.
 49. Theplanarizing machine of claim 45 wherein the web comprises a polymericmatrix material, and the web has a specific gravity of approximately0.6-0.8, a compressibility of approximately 2-7%, and a hardness ofapproximately 52-60 Shore D.
 50. The planarizing machine of claim 45wherein the web comprises a polymeric matrix material and a plurality ofabrasive particles fixed to the polymeric material, the abrasiveparticles being fixed to the polymeric material at least at theplanarizing surface.
 51. A method of planarizing a microelectronicsubstrate assembly, comprising: pressing the substrate assembly againsta planarizing surface of a seamless web by supporting the web with atable defining a planarizing zone and applying a downforce against thesubstrate; moving at least one of the substrate assembly with respect tothe web for removing material from the substrate; and sliding the webacross the table to move one portion of the web out of the planarizingzone and to move another portion of the web into the planarizing zonewithout removing the web from the table.
 52. In the fabrication ofmicroelectronic devices, a method of planarizing a microelectronicsubstrate assembly, comprising: pressing the substrate assembly againsta pad of pad material having a planarizing surface and a length toextend beyond a planarizing table and be wrapped around a roller whenthe pad is mounted to a planarizing machine, the pad being a seamlessweb formed from a single molded body of the pad material; and moving atleast one of the substrate assembly or the pad with respect to the otherby translating at least one of the substrate or the pad.